Conventionally, for example, a configuration as shown in the following Patent Document 1 is known as a bottle formed in a bottomed cylindrical shape using a synthetic resin material. In this bottle, a bottom wall portion of a bottom portion includes a grounding portion located at an outer circumferential edge; a rising circumferential wall portion that is continuous with the grounding portion from a radial inner side of the bottle and extends upward; and a movable wall portion that protrudes from an upper end of the rising circumferential wall portion toward a radial inner side of the bottle. In this bottle, the movable wall portion turns upward and moves rotationally around a connected portion to the rising circumferential wall portion, thereby absorbing decompression within the bottle.